Wikipedia (and other) articles of interest

1) Sun. How much do you really know about this thing? Do you know as much as you should?

2) Frog. More than 5,000 species are described, I had no idea there were that many. From the article:

“The skin of a frog is permeable to oxygen and carbon dioxide, as well as to water. There are a number of blood vessels near the surface of the skin. When a frog is underwater, oxygen is transmitted through the skin directly into the bloodstream. On land, adult frogs use their lungs to breathe. Their lungs are similar to those of humans, but the chest muscles are not involved in respiration, and there are no ribs or diaphragm to support breathing. Frogs breathe by taking air in through the nostrils (which often have valves which close when the frog is submerged), causing the throat to puff out, then compressing the floor of the mouth, which forces the air into the lungs.” […] “Frogs are known for their three-chambered heart, which they share with all tetrapods except birds, crocodilians and mammals. In the three-chambered heart, oxygenated blood from the lungs and de-oxygenated blood from the respiring tissues enter by separate atria, and are directed via a spiral valve to the appropriate vessel—aorta for oxygenated blood and pulmonary artery for deoxygenated blood. This special structure is essential to keeping the mixing of the two types of blood to a minimum, which enables frogs to have higher metabolic rates, and to be more active than otherwise.”

3) Qin Shi Huang. The first emperor of a unified China. Also it seems a really unpleasant human being.

About me/this blog

This blog is mainly a site where I keep track of and share some of the stuff I read and learn. Only a small subset of the posts on this blog deal with economics – I have diverse interests, and as the category cloud in the sidebar below illustrates this blog contains posts about all kinds of stuff: Mathematics, physics, statistics, geology, geography, health care and medicine, psychology, evolutionary biology, genetics, history, anthropology, archaeology, chess, …

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Goodreads Quotes

"Happiness and its anticipation are […] proximate mechanisms that lead us to perform and repeat acts that in the environments of history, at least, would have led to greater reproductive success." (Richard D. Alexander)